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Subject: Re: [RFC v1 13/26] x86/tdx: Handle MWAIT, MONITOR and WBINVD
To:     Andy Lutomirski <luto@kernel.org>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Dave Hansen <dave.hansen@intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Kirill Shutemov <kirill.shutemov@linux.intel.com>,
        Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
        Dan Williams <dan.j.williams@intel.com>,
        Raj Ashok <ashok.raj@intel.com>,
        Sean Christopherson <seanjc@google.com>,
        LKML <linux-kernel@vger.kernel.org>
References: <cover.1612563142.git.sathyanarayanan.kuppuswamy@linux.intel.com>
 <f443f4a2d80ea3717bd1865ae61cec2a100805c3.1612563142.git.sathyanarayanan.kuppuswamy@linux.intel.com>
 <CALCETrWQm+4ocEjDM2e1z=ewmjf4r--6UeqnTwKEtKRa_o-mNg@mail.gmail.com>
From:   "Kuppuswamy, Sathyanarayanan" 
        <sathyanarayanan.kuppuswamy@linux.intel.com>
Message-ID: <64109360-c45b-2a2f-b5c0-956386fc7168@linux.intel.com>
Date:   Fri, 5 Feb 2021 15:54:33 -0800
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Hi Andy,

On 2/5/21 3:43 PM, Andy Lutomirski wrote:
> MWAIT turning into NOP is no good.  How about suppressing
> X86_FEATURE_MWAIT instead?
Yes, we can suppress it in tdx_early_init().

  + setup_clear_cpu_cap(X86_FEATURE_MWAIT);

But do you want to leave the MWAIT #VE handler as it as
(just in case)?


-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer